Manufacturing method of semiconductor apparatus

ABSTRACT

The manufacturing method of a semiconductor apparatus has a step for carrying in the substrate into the processing chamber; a step for heating the processing chamber and the substrate to the predetermined temperature; and a gas supply and exhaust step for supplying and exhausting desired gas into and from the processing chamber, wherein the gas supply and exhaust step repeats by the predetermined times a first supply step for supplying silicon-type gas and hydrogen gas into the processing chamber; a first exhaust step for exhausting at least said silicon-type gas from the processing chamber; a second supply step for supplying chlorine gas and hydrogen gas into the processing chamber; and a second exhaust step for exhausting at least the chlorine gas from the processing chamber.

CROSS REFERENCED TO RELATED APPLICATIONS

The present application is a Divisional Application of application Ser.No. 12/060,511, filed Apr. 1, 2008; which claims priorities fromJapanese applications JP2007-096059 filed on Apr. 2, 2007, JP2008-75763filed on Mar. 24, 2008, the contents of which are hereby incorporated byreference into this application.

BACKGROUND OF THE INVENTION

The present invention relates to a manufacturing method of asemiconductor apparatus for manufacturing a semiconductor apparatus bycarrying out processing such as thin film formation, impurity diffusion,annealing processing and etching on a substrate such as a silicon wafer,a glass substrate.

As one of semiconductor apparatuses, there is a MOSFET (Metal OxideSemiconductor Field Effect Transistor), which is a polymerized structureof a metal, an oxide film and a semiconductor, and in recent years, ithas been progressing to attain finer patterning and higher performanceof MOSFET.

As a problem in attaining the finer patterning and higher performanceMOSFET, there is decrease in contact resistance or the like, and as onemethod for solving this problem, there is a method of selectivelygrowing a silicon epitaxial film on a source/drain.

Conventionally, growth of a silicon epitaxial film has been carried outby using SiH₂Cl₂ and HCl and H₂, as processing gas, and by continuouslysupplying these processing gases into a processing chamber at aprocessing temperature of from 750° C. to 850° C.

The above processing temperature of 750° C. to 800° C. is hightemperature, and accompanying with the finer patterning and higherperformance, influence of thermal damage and thermal budget on thesubstrate element increases, which makes a cause of inhibition of makinga higher performance device, or a cause of lower yield.

As conventional technology, JP-A-2003-86511 and JP-A-5-21357 areincluded.

SUMMARY OF THE INVENTION

It is an object of the present invention, in consideration of the abovesituation, to provide a manufacturing method of a semiconductorapparatus, which is capable of formation of a high quality film at lowtemperature, and attains enhancements of device performance as well asyield.

The present invention relates to a manufacturing method of asemiconductor apparatus for selectively growing an epitaxial film at asilicon surface of a substrate, by storing the substrate having at leastthe silicon surface and an insulating surface at the surface thereof,into a processing chamber, and by using a substrate processing apparatusfor heating an atmosphere of the inside of the processing chamber andthe substrate to a predetermined temperature by a heating unit installedoutside, comprising a step for carrying in the substrate into theprocessing chamber; a step for heating the atmosphere of the inside ofthe processing chamber and the substrate to the predeterminedtemperature; and a gas supply and exhaust step for supplying andexhausting desired gas into and from the processing chamber, wherein thegas supply and exhaust step repeats by the predetermined times andcarries out, a first supply step for supplying silicon-containing gasand hydrogen gas into the processing chamber; a first exhaust step forexhausting at least the silicon-containing gas from the processingchamber; a second supply step for supplying chlorine gas and hydrogengas into the processing chamber; and a second exhaust step forexhausting at least the chlorine gas from the processing chamber.

According to the present invention, there is provided a manufacturingmethod of a semiconductor apparatus for selectively growing an epitaxialfilm at a silicon surface of a substrate, by storing the substratehaving at least the silicon surface and an insulating surface at thesurface thereof into a processing chamber, and by using a substrateprocessing apparatus for heating an atmosphere of the inside of theprocessing chamber and the substrate to a predetermined temperature by aheating unit installed outside, comprising a step for carrying in thesubstrate into the processing chamber; a step for heating the atmosphereof the inside of the processing chamber and the substrate to thepredetermined temperature; and a gas supply and exhaust step forsupplying and exhausting desired gas into and from the processingchamber, wherein the gas supply and exhaust step repeats by thepredetermined times and carries out, a first supply step for supplyingsilicon-containing gas and hydrogen gas into the processing chamber; afirst exhaust step for exhausting at least the silicon-containing gasfrom the processing chamber; a second supply step for supplying chlorinegas and hydrogen gas into the processing chamber; and a second exhauststep for exhausting at least the chlorine gas from the processingchamber, therefore, throughput is enhanced because a gas purge step byinert gas can be omitted in a step before or after the second supplystep, and also, excellent effect of enhancing processing uniformity isexerted, because processing by chlorine gas is carried out by supplyinghydrogen gas along with chlorine gas.

Other objects, features and advantages of the invention will becomeapparent from the following description of the embodiments of theinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an example of a substrateprocessing apparatus relevant to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a processing furnace usedin the substrate processing apparatus.

FIG. 3 is a flowchart of a processing step relevant to the presentinvention.

FIG. 4A is a flowchart showing an example of a first film-formation stepof the present invention.

FIG. 4B is a flowchart showing an example of a second film-formationstep of the present invention.

FIG. 5 is an explanation drawing showing a film-formation state in thepresent invention.

FIG. 6 is a drawing showing etching data of a comparative experiment ofthe present invention.

DESCRIPTION OF THE EMBODIMENTS

Explanation will be given below on embodiments for carrying out thepresent invention with reference to drawings.

First, explanation will be given, in FIG. 1, on a substrate processingapparatus, where the present invention is carried out.

In FIG. 1, “1” represents a substrate processing apparatus, “2”represents a substrate storage container (cassette), and a substrate(wafer) “3” such as a silicon wafer, which is processed by the substrateprocessing apparatus 1, is carried-in or carried-out in a stored statein the cassette 2 in required pieces, for example, 25 pieces.

At the lower part of a front side wall 5 of a housing 4 of the substrateprocessing apparatus 1, a front side maintenance port 6 is installed asan opening part for maintenance, and said front side maintenance port 6is designed to be capable of opening and closing by a front sidemaintenance door (not shown). At the upward of the front sidemaintenance port 6, there is installed a substrate storage containergateway 8 for carrying in and carrying out the cassette 2, and thesubstrate storage container gateway 8 is designed to be opened andclosed by a gateway opening and closing facility (a front shutter) (notshown).

Adjacent to the inside of the housing 4, and the substrate storagecontainer gateway 8, a substrate storage container receiving apparatus(a cassette receiving stage) 11 is installed, and facing the cassettereceiving stage 11, there are installed a lower substrate storagecontainer storage shelf (a cassette shelf) 12, and an upper substratestorage container storage shelf (a buffer cassette shelf) 13, forstoring the required pieces of the cassettes 2.

Between the cassette receiving stage 11 and the cassette shelf 12 andthe buffer cassette shelf 13, a substrate storage container carryingapparatus (a cassette carrying apparatus) 14 is installed. Said cassettecarrying apparatus 14 is provided with a traverse facility, a hoistingfacility and a rotation facility, and is capable of carrying thecassette 2 in required position, between the cassette receiving stage 11and the cassette shelf 12 and the buffer cassette shelf 13, by acooperation of the traverse facility, the hoisting facility and therotation facility.

At the backward and the lower part of the inside of the housing 4, aload lock chamber 15, which is an air-tight container, is installed, andat the upper side of the load lock chamber 15, a processing furnace 16is installed. The processing furnace 16 is provided with an air-tightprocessing chamber 17, and the processing chamber 17 is connectedair-tightly to the load lock chamber 15, and a furnace port part at thelower end of the processing chamber 17 is designed to be blockableair-tightly by a furnace port gate valve 20.

At the inside of the load lock chamber 15, a substrate holding tool (aboat) 18 can be stored, and said boat 18 is made of a heat resistantmaterial, for example, quartz or silicon carbide or the like, which isdesigned to be capable of holding the wafer 3 in multiple stages, in ahorizontal position. In addition, it is preferable that a shelf forsupporting the wafer 3 is casted in a ring-like shape. It should benoted that at the lower part of the boat 18, there are installed inmultiple stages and in a horizontal position, multiple pieces of heatinsulating plates (not shown) as a heat insulating member with acircular plate-like shape, made of a heat resistant material of, forexample, quartz or silicon carbide or the like, so as to inhibit heatradiation downward.

In addition, there is installed a substrate holding tool hoistingfacility (a boat elevator) 19 for supporting the boat 18, and formounting and dismounting said boat 18 to and from the processing chamber17, at the load lock chamber 15.

Said load lock chamber 15 is provided with a substrate transfer port 21for transferring the wafer 3 onto the boat 18, and said substratetransfer port 21 is released and also blocked air-tightly by a gatevalve 25. At the load lock chamber 15, there is connected a gas supplysystem 22 for supplying inert gas such as nitrogen gas, and alsoconnected an exhaust apparatus (not shown) for exhausting the inside ofthe load lock chamber 15 to make negative pressure.

Between the load lock chamber 15 and the cassette shelf 12, a substratetransfer apparatus (a substrate transfer machine) 23 is installed, andsaid substrate transfer machine 23 is provided with required pieces (forexample, 5 pieces) of substrate holding plate 24 for mounting andholding the wafer 3, as well as provided with an hoisting facility partfor hoisting the substrate holding plates 24, a rotation facility partfor rotation thereof, and a forward and backward movement facility partfor making forward and backward movement thereof.

The substrate transfer machine 23 is designed so that a substrate istransferred between the boat 18 in a descending state and the cassetteshelf 12, via the substrate transfer port 21, by cooperation of thehoisting facility part, the rotation facility part and the forward andbackward movement facility part.

It should be noted that at a required position of the inside of thehousing 4, for example, a clean unit 26 is installed facing the buffercassette shelf 13, and flow of clean atmosphere is formed in the insideof the housing 4 by said clean unit 26.

Explanation will be given below on actuation of the substrate processingapparatus 1.

The substrate storage container gateway 8 is released by a front shutter(not shown), and the cassette 2 is carried in from the substrate storagecontainer gateway 8. The cassette 2 carried in is mounted so that thewafer 3 takes a vertical position and a gateway of the wafer 3 faces anupward direction.

Then, by the cassette carrying apparatus 14, the cassette 2 is carriedto a designated shelf position of the cassette shelf 12 or the buffercassette shelf 13. The cassette 2 stored at the cassette shelf 12 or thebuffer cassette shelf 13 is set to take horizontal position and thegateway faces the substrate transfer machine 23. In addition, afterbeing temporarily stored, the cassette 2 is transferred from the buffercassette shelf 13 to the cassette shelf 12 by the cassette carryingapparatus 14.

Inside of the load lock chamber 15 is made in an atmospheric pressurestate in advance, and the boat 18 is descended to the inside of the loadlock chamber 15 by the boat elevator 19. By the gate valve 25, thesubstrate transfer port 21 is released, and by the substrate transfermachine 23, the wafer 3 is transferred into the boat 18 from thecassette 2.

When previously designated pieces of the wafers 3 are charged onto theboat 18, the substrate transfer port 21 is closed by the gate valve 25,and a pressure of the load lock chamber 15 is reduced by vacuuming withan exhaust apparatus. When the pressure of the load lock chamber 15 isreduced to the same pressure in the processing chamber 17, the furnaceport part of the processing chamber 17 is released by the furnace portgate valve 20, and the boat 18 is charged into the processing chamber 17by the boat elevator 19.

The wafer 3 is subjected to predetermined processing by carrying out theheating of the wafer 3, the introduction of processing gas into theprocessing chamber 17 and exhaustion or the like.

After processing, the boat 18 is taken out by the boat elevator 19, andstill more, after pressure in the load lock chamber 15 is restored toatmospheric pressure, the gate valve 25 is opened. After that, the wafer3 and the cassette 2 are carried out to the outside of the housing 4 byreversed procedure of the above.

Then explanation will be given, in FIG. 2, on the processing furnace 16and the boat elevator 19.

As shown in FIG. 2, the processing furnace 16 has a heater 31 as heatingfacility. Said heater 31 has a circular cylinder-like shape and isconfigured by a heater element line and an insulating member installedat the circumference thereof, and is installed vertically by beingsupported by a holding body not shown.

At the vicinity of the heater 31, a temperature sensor (not shown) isinstalled as a temperature detecting body for detecting temperature inthe processing chamber 17. A temperature control part 45 is electricallyconnected to the heater 31 and the temperature sensor, and it isconfigured so as to control in desired timing so that temperature in theprocessing chamber 17 becomes desired temperature distribution byadjusting a current-carrying state to the heater 31 based on temperatureinformation detected by the temperature sensor.

At the inside of the heater 31, a reaction tube 32 is installedconcentrically with the heater 31. Said reaction tube 32 is made of aheat resistant material such as quartz (SiO₂) or silicon carbide (SiC),and is formed in a circular cylinder-like shape with the upper endblocked and the lower end opened. The reaction tube 32 configures theprocessing chamber 17, stores the boat 18, and the wafer 3 is stored inthe processing chamber 17 in a state held in the boat 18.

At the downward of the reaction tube 32, a manifold 33 is installedconcentrically with the reaction tube 32, and the reaction tube 32 isinstalled at the manifold 33. Said manifold 33 is made of, for example,stainless steel or the like, and is formed in a circular cylinder-likeshape with the upper end and the lower end opened. It should be notedthat between the manifold 33 and the reaction tube 32, an O-ring isinstalled as a sealing member. The manifold 33 is supported by a holdingbody, for example, the load lock chamber 15, and thereby the reactiontube 32 becomes in a vertically installed state. A reaction container isformed by said reaction tube 32 and the manifold 33.

At said manifold 33, an exhaust pipeline 34 is installed, as well as agas supply pipeline 35 is installed so as to pass through. The gassupply pipeline 35 is branched into three at the upstream side, andconnected to a first gas supply source 42, a second gas supply source 43and a third gas supply source 44, via valves 36, 37 and 38, and MFCs 39,40 and 41 as gas flow amount control apparatus, respectively. It isdesigned that the first gas supply source 42 supplies, for example,silane-type gas or halogen-containing silane-type gas as processing gas,the second gas supply source 43 supplies hydrogen gas as processing gasor carrier gas, and in addition, the third gas supply source 44 suppliesnitrogen gas as carrier gas or purging gas.

A gas flow amount control part 46 is electrically connected to the MFCs39, 40 and 41, and the valves 36, 37 and 38, and said gas flow amountcontrol part 46 is configured to control in desired timing so that flowamount of supplying gas becomes desired flow amount.

At the lower stream side of the exhaust pipeline 34, a vacuum exhaustionapparatus 48 such as a vacuum pump is connected, via a pressure sensoras a pressure detector not shown, and an APC valve 47 as a pressureregulator. As the vacuum exhaustion apparatus 48, it is preferable thata ternary vacuum pump system with high exhaustion capability, forexample, a molecular turbo pump+a machine booth and a pump+a dry pump orthe like are used.

A pressure control part 49 is electrically connected to the pressuresensor and the APC valve 47, and said pressure control part 49 isconfigured so as to control in desired timing so that pressure of theprocessing chamber 17 becomes desired pressure by adjusting degree ofopening of the APC valve 47, based on pressure detected with thepressure sensor.

In the configuration of the processing furnace 16, the first processinggas is supplied from the first gas supply source 42, and is introducedinto the processing chamber 17 by the gas supply pipeline 35, via thevalve 36, after adjustment of flow amount thereof by the MFC 39. Thesecond processing gas is supplied from the second gas supply source 43,and is introduced into the processing chamber 17 by the gas supplypipeline 35, via the valve 37, after adjustment of flow amount thereofby the MFC 40. The third processing gas is supplied from the third gassupply source 44, and is introduced into the processing chamber 17 bythe gas supply pipeline 35, via the valve 38, after adjustment of flowamount thereof by the MFC 41. In addition, gas in the processing chamber17 is exhausted from the processing chamber 17 by the vacuum exhaustionapparatus 48 connected to the exhaust pipeline 34.

Then explanation will be given on the boat elevator 19.

The drive facility part 51 of said boat elevator 19 is installed at theside wall of the load lock camber 15.

The drive facility part 51 is provided with a guide shaft 52 installedin parallel and a ball screw 53, and said ball screw 53 is supported ina free-rotation state, and is designed to be rotated by a hoisting motor54. A hoisting platform 55 is engaged slidably to the guide shaft 52, aswell as screwed in to the ball screw 53, and at the hoisting platform55, a hollow hoisting shaft 56 is installed vertically in parallel tothe guide shaft 52.

Said hoisting shaft 56 is extended inside by passing thorough freely aceiling surface of the load lock chamber 15, and at the lower endthereof, a hollow drive part storage case 57 is installed air-tightly. Abellows 58 is installed so as to cover the hoisting shaft 56 innon-contact state, and the upper end of the bellows 58 is fixed at thelower surface of the hoisting platform 55, and the lower end of thebellows 58 is fixed at the upper surface of the load lock chamber 15,each air-tightly, and a free passing through part of the hoisting shaft56 and said hoisting shaft 56 are sealed air-tightly.

At the ceiling part of the load lock chamber 15, a furnace port 59 isinstalled concentrically with the manifold 33, and the furnace port 59is designed to be blockable air-tightly by a seal cap 61. Said seal cap61 is, for example, made of metal such as stainless steel, and formed ina circular disk-like shape, and fixed air-tightly at the upper surfaceof the drive part storage case 57.

The drive part storage case 57 has an air-tight structure, and theinside thereof is isolated from atmosphere in the load lock chamber 15.At the inside of the drive part storage case 57, a boat rotationfacility 62 is installed, and the rotation axis of the boat rotationfacility 62 is extended upward by passing through freely a top panel ofthe drive part storage case 57 and the seal cap 61, and at the upper endthereof, a boat mounting platform 63 is fixed, and the boat 18 ismounted on the boat mounting platform 63.

The seal cap 61 and the boat rotation facility 62 are each cooled by awater-cooling-type cooling facilities 64 and 65, and a cooling-waterpipeline 66 to the cooling facilities 64 and 65 is connected to anexternal cooling water source (not shown) after passing the hoistingshaft 56. In addition, power supply to the boat rotation facility 62 iscarried out via a power supply cable 67 wired through the hoisting shaft56.

A drive control part 68 is electrically connected to the boat rotationfacility 62 and the hoisting motor 54, and it is configured so as tocontrol in desired timing to perform desired motion.

The temperature control part 45, the gas flow amount control part 46,the pressure control part 49 and the drive control part 68 configurealso an operation part and an input-output part, and electricallyconnected to a main control part 69 for controlling whole part of thesubstrate processing apparatus 1.

As described above, a drive part of the boat elevator 19, the boatrotation facility 62, the cooling-water pipeline 66, the power supplycable 67 and the like are isolated from the inside of the load lockchamber 15, by the drive part storage case 57 and the bellows 58,therefore, there is no risk that the wafer 3 is contaminated by organicsubstances and particles emitted from a driving system and a wiringsystem, by residual heat in vacuuming of the load lock chamber 15, or inreleasing of the furnace port gate valve 20.

Then, explanation will be given on a method for carrying outfilm-formation processing on a substrate such as the wafer 3, as onestep of production steps of a semiconductor device, by using theprocessing furnace 16, with reference to FIG. 3.

It should be noted that in the following explanation, movement of eachpart configuring the substrate processing apparatus 1 is controlled bythe main control part 69.

First, a naturally oxidized film on the surface of the wafer 3 isremoved with diluted hydrofluoric acid, and at the same time, thesurface was subjected to hydrogen termination (STEP: 01).

The boat 18 is descended by the boat elevator 19, and the furnace port59 is blocked air-tightly by the furnace port gate valve 20. Thesubstrate transfer port 21 is released by the gate valve 25, in a statethat the inside of the load lock chamber 15 becomes a state having thesame pressure as that in the outside of the load lock chamber 15. By thesubstrate transfer machine 23, predetermined pieces of the wafers 3 arecharged onto the boat 18 (STEP: 02).

The substrate transfer port 21 is blocked air-tightly by the gate valve25, and the inside of the load lock chamber 15 is subjected to repeatedvacuuming and purging by inert gas (for example, nitrogen gas) to removeoxygen and moisture in the atmosphere of the inside of the load lockchamber 15.

Then, the furnace port 59 is released by the furnace port gate valve 20,and the boat elevator 19 is driven. The ball screw 53 is rotated by thedrive of the hoisting motor 54, and the drive part storage case 57 isascended via the hoisting platform 55 and the hoisting shaft 56, and theboat 18 is charged into the processing chamber 17. In this state, theseal cap 61 blocks the furnace port 59 air-tightly via an O-ring.

It should be noted that temperature of the processing chamber 17 atcharging is set at 200° C. or around 200° C., to prevent surfaceoxidation of the wafer 3 (STEP: 03).

The inside of the processing chamber 17 is subjected to vacuumexhausting by the vacuum exhaustion apparatus 48, so as to becomedesired pressure (degree of vacuum). In this case, pressure in theprocessing chamber 17 is measured with a pressure sensor, and based onthis pressure measured, the APC valve 47 is feed-back controlled. Inaddition, the processing chamber 17 is heated by the heater 31 so thatthe inside thereof becomes desired temperature and desired temperaturedistribution, and the heating state is feed-back controlled by thetemperature control part 45, based on temperature information detectedby the temperature sensor. Subsequently, the wafer 3 is rotated byrotation of the boat 18, by the boat rotation facility 62.

When the boat 18 is charged into the processing chamber 17 andexhaustion is completed, the processing chamber is set at pre-treatmenttemperature (it is usually the same as film-formation temperature,however, in treatment with only H₂ gas, it is from 750 to 800° C.Treatment under raising temperature after charging the boat is alsopossible), and pre-treatment is carried out. For the pre-treatment,hydrogen gas or silane-type gas (for example, SiH₄), orhalogen-containing silane gas or hydrogen chloride gas, or combinationgas thereof is supplied along with inert gas or carrier gas such ashydrogen gas, from the first gas supply source 42, the second gas supplysource 43 and the third gas supply source 44, via the MFCs 39, 40 and 41(STEP: 04).

By carrying out the pre-treatment, interface oxygen and carbon densitycan be reduced, and high quality interface can be formed between asemiconductor substrate and a thin film.

After completion of the pre-treatment, residual gas in the processingchamber 17 is removed by carrier gas such as hydrogen.

Temperature of the processing chamber 17 is adjusted from pre-treatmenttemperature to film-formation temperature. In this time, hydrogen gas isflown to the processing chamber 17, as carrier gas, to preventcontamination caused by reversed diffusion from an exhaustion system(STEP: 05).

When temperature of the processing chamber 17 is stabilized atfilm-formation temperature, processing gas is introduced to carry outfilm-formation processing. Each processing gas is supplied from thefirst gas supply source 42, the second gas supply source 43 and thethird gas supply source 44. In addition, after adjustment the degree ofopening of the MFCs 39, 40 and 41, so as to attain desired flow amount,the valves 36, 37 and 38 are opened, and each processing gas isintroduced into the processing chamber 17 from the upper part of theprocessing chamber 17, by flowing through the gas supply pipeline 35.

As processing gas to be introduced, silane-type gas (SiH₄), or halogengas-containing gas or silane-type gas mixed with hydrogen gas, orhalogen-containing silane-type gas mixed with hydrogen gas is used. Inthe case where processing gas is SiH₄, film-formation temperature in theprocessing chamber 17 is adjusted at from 500 to 700° C.

Introduced processing gas passes through the inside of the processingchamber 17, and is exhausted from the exhaust pipeline 34. Processinggas contacts with the wafer 3 in passing through the inside of theprocessing chamber 17, to grow and deposit an EPI film on the surface ofthe wafer 3. In addition, unnecessary nuclei on an insulating film areremoved by etching processing. A predetermined film is formed byrepeating by the predetermined time's film-formation and etching (STEP:06).

When previously set time elapsed, inert gas is supplied from an inertgas supply source not shown, and the inside of the processing chamber 17is replaced with inert gas, as well as pressure in the processingchamber 17 is restored to normal pressure (so as to be the same pressureas that of the inside of the load lock chamber 15) (STEP: 07).

After that, temperature in the processing chamber 17 is lowered to atemperature of, for example, 200° C., that is, temperature at which thesurface of the wafer 3 is not oxidized (STEP: 08).

The seal cap 61 is descended by the boat elevator 19, and the boat 18 iscarried out from the furnace port 59 into the inside of the load lockchamber 15 with opening of the furnace port 59. The furnace port 59 isblocked by the furnace port gate valve 20. After the wafer 3 is cooledto required temperature in the load lock chamber 15, the substratetransfer port 21 is released to take out the processed wafer 3 from theboat 18 by the substrate transfer machine 23 (refer to FIG. 1) (STEP:09).

Explanation will be given, in FIGS. 4A and 4B, on an example offilm-formation step of the STEP: 06.

First, FIG. 4A shows an example of the first film-formation step, andshows the case where Cl₂ is introduced by using N₂ as carrier gas, incarrying out etching.

First, SiH₄ and H₂ are introduced for film-formation (STEP: 11).

By simultaneous introduction of SiH₄ and H₂, the processing chamber 17is maintained clean, and in addition, although SiH₄ is decomposed toSi+2 H₂, by presence of H₂, which was supplied simultaneously, thedecomposition action is inhibited. That is, by simultaneous introductionof SiH₄ and H₂, decomposition degree of SiH₄ can be controlled.

After that, SiH₄ is excluded from the processing chamber 17 by H₂ purge(STEP: 12). The H₂ purge removes processing gas, as well as brings thesubstrate surface H-termination.

Then, after introduction of nitrogen gas for N₂ purge (STEP: 13), Cl₂and N₂ are introduced to remove (etching) unnecessary nuclei on theinsulating film (STEP: 14). Then, Cl₂ is excluded from the processingchamber 17, by N₂ purging (STEP: 15), and still more N₂ is excluded byH₂ purging (STEP: 16).

The STEP: 11 to the STEP: 16 are repeated to form a desired film.

Still more, in the case of forming an impurity diffused film, doping gassuch as PH₃, B₂H₆, BCl₃ is introduced in the midway of the STEP: 11 tothe STEP: 16.

In the present step, because SiH₄ is used as film-formation gas,film-formation temperature can be set as low as from 500 to 700° C., andinfluence of thermal damage or thermal budget on a substrate element canbe alleviated. In addition, in the case where Si₂H₆ is used as afilm-forming gas, it is possible to set film-formation temperature aslow as from 450 to 700° C. compared with the case where SiH₄ is used.

Then, FIG. 4B shows an example of the second film-formation step, andshows the case where Cl₂ is introduced by using H₂ as carrier gas, incarrying out etching.

First, SiH₄ and H₂ are introduced for film-formation (STEP: 21). In thiscase, it is preferable that flow amount of SiH₄ gas is from 100 to 500sccm, flow amount of H₂ gas is from 100 to 20000 sccm, processingtemperature is from 500 to 700° C., and processing pressure is equal toor lower than 1000 Pa.

The fact that decomposition degree of SiH₄ is controlled by simultaneousintroduction of SiH₄ and H₂, is similar to explanation in FIG. 4A.

After that, SiH₄ is excluded from the processing chamber 17 by H₂ purge(STEP: 22). The H₂ purge removes processing gas, as well as brings thesubstrate surface H-termination.

Then, Cl₂ and H₂ are introduced to remove (by etching) unnecessarynuclei on the insulating film (STEP: 23). In this case, it is preferablethat flow amount of Cl₂ gas is from 50 to 200 sccm, flow amount of H₂gas is from 100 to 20000 sccm, processing temperature is from 500 to700° C., and processing pressure is equal to or lower than 1000 Pa.

Then, Cl₂ is excluded by H₂ purge (STEP: 24). Because Cl₂ is dilutedwith H₂ in etching, uniformity of etching is enhanced.

STEP: 21 to STEP: 24 are repeated to form a desired film.

Still more, in the case of forming an impurity diffused film, doping gassuch as PH₃, B₂H₆, BCl₃ is introduced in the midway of the STEP: 21 tothe STEP: 24.

In addition, depending on film-formation state, a flow amount of one ormore kinds of gas among SiH₄, Cl₂ and H₂ is changed in the gasintroduction step in the STEP: 21 and the STEP: 23.

For example, by increasing the flow amount of SiH₄, film-formation rateis increased, and by increasing the flow amount of Cl₂, etching amountis increased. Therefore, by changing the flow amount of gas, thefollowing embodiments become possible.

For example, SiN and SiO have characteristics that growth of an Sinucleus is easy, and growth of an Si nucleus is difficult, respectively.Therefore, for example, an insulating film SiO is formed in anoverlapped state on an insulating film SiN, and on a substrate with theend surfaces of both insulating films exposed (refer to FIG. 5), in theinitial film-formation processing, etching rate is strengthened(film-formation rate is slowed), and when thickness of the film formedis over thickness of the SiN, etching rate is weakened to be able toincrease film-formation rate.

In addition, for example, when impurity is present on an Si surface,which is a target of film-formation processing, the film tends to bepoly silicon film, therefore, etching rate is strengthened at the earlygrowth stage to carry out film-formation while removing the impurity,and when an EPI film is formed in certain degree, etching rate isweakened to increase film-formation rate.

It should be noted that by increasing processing pressure, etchingaction and film-formation action are increased, therefore also bychanging processing pressure during the film-formation processing, theabove embodiment can be obtained.

Also in the second film-formation step, because SiH₄ is used asfilm-formation gas, film-formation temperature can be set as low as from500 to 700° C., and influence of thermal damage or thermal budget on asubstrate element can be alleviated. In addition, in the case whereSi₂H₆ is used as a film-forming gas, it is possible to setfilm-formation temperature as low as from 450 to 700° C. compared withthe case where SiH₄ is used.

Still more, in the second film-formation step, because Cl₂ and H₂ areintroduced as processing gas in etching, purging of N₂ is not necessarybefore or after the etching step, and a purge step of N₂ can be omitted,therefore simplification of the film-formation step and shortening ofthe processing time are possible, and throughput is enhanced.

In addition, uniformity of film-formation in an example of the firstfilm-formation step is about 20%, and uniformity of film-formation in anexample of the second film-formation step is from 5 to 10%, thereforeenhancement of quality of a film formed was obtained in the example ofthe second film-formation step as compared with the example of the firstfilm-formation step.

In FIG. 6, when the etching is carried out using Cl₂ to the monitorwafer formed Poly-Si film, there are shown the experimental results thatthe etching rate and the uniformity in wafer surface of etching amountare compared, respectively, in the case where N₂ is used and H₂ is usedas a carrier gas.

In FIG. 6, marks ▴ and  represent etching rate, and marks A and orepresent uniformity in wafer surface of etching amount.

The experiment was carried out under the following conditions:

Processing temperature: 620° C.

Total pressure: 2 Pa

Cl₂ partial pressure: 0.04 Pa

N₂ partial pressure: 1.96 Pa

H₂ partial pressure: 1.96 Pa

Each value obtained by the experiment carried out under the aboveconditions is shown in Table 1. From these results, it is understoodthat etching by the case used H₂ as a carrier gas provides lower etchingrate and better uniformity in surface of etched amount, as compared withetching by the case used N₂ as a carrier gas. Therefore, it can be saidthat etching by the case used H₂ as a carrier gas is capable ofenhancing uniformity of film-formation.

In addition, from FIG. 6, it is understood that etching by the case usedH₂ as a carrier gas is capable of enhancing also uniformity between thewafer.

TABLE 1 N₂ dilution H₂ dilution Etching rate (Å/min) 12 to 16 10 to 12Uniformity of etching amount ~±10 ~±5 within the surface (%)

Next, it is described the reason why, when the etching is carried outusing Cl₂ as a carrier gas, the case used H₂ as a carrier gas providesbetter uniformity of etching, as compared with the case used N₂ as acarrier gas.

When the etching is carried out only by Cl₂ without using carrier gas,and when the etching is carried out using N₂ as carrier gas, etching ofCl₂ becomes dominant. Therefore, etching at the edge part of a waferbecomes strong, and gas is almost consumed at the edge part, resultingin no reaching of etching gas to the center part of the wafer, whichlowers uniformity. On the other hand, when H₂ is used as a carrier gas,Cl₂ and H₂ react in the gas phase to form an intermediate, and then thereaction to form 2HCl occurs partially resulting in lowering the etchingpower. Because an intermediate of HCl is formed during the processthereof, etching gas is capable of reaching the center part of thewafer, therefore, it is considered that uniformity is improved.

In addition, it is considered to be one reason that the wafer surface iscovered with H, which then reduces etching effect of Cl and increasesamount of gas reaching to the center part of the wafer.

Further, it is described the reason why, when the etching is carried outusing H₂ as a carrier gas, the case used Cl₂ as an etching gas iseffective, as compared with the case used HCl as an etching gas.

Because the processing furnace 16 has a hot wall structure, is subjectedto etching with gas decomposed in gas phase. However, HCl takes a longtime to be decomposed at low processing temperature as in the presentapplication, therefore it is difficult to secure selectivity. On theother hand, Cl₂ provides rapid progress of thermal decomposition even inlow temperature processing, therefore Cl₂ provides higher etching rate,and is capable of securing higher selectivity.

And, the relation of this etching power does not change even in the caseof dilution with H₂, and because the case used Cl₂ as an etching gasprovides stronger etching power than the case used HCl as an etchinggas, the case used Cl₂ as an etching gas is capable of providing betterresult in low temperature processing like in the present application.

It should be noted that, because of occurrence of a reaction that anintermediate of HCl is generated in vapor phase by heat, uniformity offilm-formation can be improved by using Cl₂ as etching gas, using H₂ ascarrier gas as above. Therefore, because of a hot wall structure, whereatmosphere in the reaction tube is heated, effect of the presentapplication invention is attained.

It should be noted that explanation has been given on formation of anEPI-Si film on a substrate in the above embodiments, however, thepresent invention is capable of being carried out also in a singlecrystal film, a polycrystal film, an amorphous film or the like, or adoped single crystal film, a doped polycrystal film, a doped amorphousfilm or the like.

Still more, as a substrate processing apparatus where the presentinvention is carried out, there can be included a substrate processingapparatus in general such as a lateral-type substrate processingapparatus, and for example, also a sheet-type, hot wall-type substrateprocessing apparatus.

(Additional Statement)

In addition, the present invention includes the following embodiments.

(Additional Statement 1)

A manufacturing method of a semiconductor apparatus for selectivelyforming a thin film on a silicon substrate by a reduced pressure CVDmethod (Chemical Vapor Deposition), characterized in that the thin filmwith high quality interface is grown by intermittently supplying, in analternately repeating state, silane-type gas such as SiH₄ andhalogen-type gas such as Cl₂, together with hydrogen gas, into areaction furnace, and in addition, without making a silicon film or asilicon nucleus grown on an insulating film such as silicon nitridefilm, so as to secure selectivity.

(Additional Statement 2)

A manufacturing method of a semiconductor apparatus by changing flowamount of one or more of silane-type gas such as SiH₄ and halogen-typegas such as Cl₂, and hydrogen gas, during the repeating cycle shown inthe Additional Statement 1.

(Additional Statement 3)

A manufacturing method of a semiconductor apparatus by changing pressurein the reaction furnace during the repeating cycle shown in theAdditional Statement 1 and the Additional Statement 2.

(Additional Statement 4)

A manufacturing method of a semiconductor apparatus by introducingdoping gas such as PH₃, B₂H₆ and BCl₃ during the repeating cycle shownin the Additional Statement 1, the Additional Statement 2 and theAdditional Statement 3.

(Additional Statement 5)

A manufacturing method of a semiconductor apparatus, in any of theAdditional Statement 1, Additional Statement 2 and Additional Statement3, in introducing a silicon substrate and a tool (boat) for siliconsubstrate processing from a front chamber of a reaction furnace into thereaction furnace, where the drive axis part thereof and a boat rotationfacility part and a wiring part are isolated from the front chamber ofthe reaction furnace.

It should be further understood by those skilled in the art thatalthough the foregoing description has been made on embodiments of theinvention, the invention is not limited thereto and various changes andmodifications may be made without departing from the sprit of theinvention and the scope of the appended claims.

1. A substrate processing apparatus for selectively growing an epitaxialfilm at a surface of a substrate stored in a processing chamber, byusing at least silicon-containing gas and chlorine gas, and by supplyingalternately repeatedly said silicon-containing gas and said chlorine gasinto said processing chamber, comprising: the processing chamber forstoring the substrate; a heating unit for heating said substrate and theatmosphere of the inside of said processing chamber, installed at theoutside of said processing chamber; a gas supply unit for supplyingdesired gas into said processing chamber; an exhaust port opening atsaid processing chamber; and a control part for controlling at leastsaid heating unit and said gas supply unit, wherein said gas supply unitcomprises; a first gas supply member for supplying silicon-containinggas; a second gas supply member for supplying chlorine gas; and a thirdgas supply member for supplying hydrogen gas, and said control partcontrols said gas supply unit so that hydrogen gas is simultaneouslysupplied in case of supplying said silicon-containing gas into theinside of said processing chamber, and controls said gas supply unit sothat hydrogen gas is simultaneously supplied in case of supplying saidchlorine gas into the inside of said processing chamber.
 2. Thesubstrate processing apparatus according to claim 1, wherein saidcontrol part, in case of supplying at least said chlorine gas, controlssaid heating unit so that the atmosphere of the inside of saidprocessing chamber and said substrate is heated at equal to or lowerthan 700° C.